public static string DownloadText(this IStorageBlob blob)
{
if (blob == null)
{
throw new ArgumentNullException("blob");
}
using (Stream stream = blob.OpenReadAsync(CancellationToken.None).GetAwaiter().GetResult())
using (TextReader reader = new StreamReader(stream, StrictEncodings.Utf8))
{
return(reader.ReadToEnd());
}
}
private static async Task<string> ReadBlobAsync(IStorageBlob blob, CancellationToken cancellationToken)
{
// Beware! Blob.DownloadText does not strip the BOM!
try
{
using (var stream = await blob.OpenReadAsync(cancellationToken))
using (StreamReader sr = new StreamReader(stream, detectEncodingFromByteOrderMarks: true))
{
cancellationToken.ThrowIfCancellationRequested();
string data = await sr.ReadToEndAsync();
return data;
}
}
catch
{
return null;
}
}
/// <summary>
/// Given a log file (as a blob), parses it and return a collection of log entries matching version 1.0
/// of the Storage Analytics Log Format.
/// </summary>
/// <param name="blob">Object representing a cloud blob with Storage Analytics log content.</param>
/// <param name="cancellationToken">A token to monitor for cancellation request.</param>
/// <returns>Collection of successfully parsed log entries.</returns>
/// <exception cref="FormatException">If unable to parse a line in given log.</exception>
/// <seealso cref="StorageAnalyticsLogEntry"/>
/// <remarks>
/// The method scans log file lines one at a time.
/// First it attempts to detect a line format version and throws an exception if failed to do so.
/// It skips all lines with version different than supported one, i.e. 1.0.
/// Then it calls TryParseLogEntry to create a log entry out of every line of supported version and throws
/// an exception if the parse method returns null.
/// </remarks>
public async Task <IEnumerable <StorageAnalyticsLogEntry> > ParseLogAsync(IStorageBlob blob,
CancellationToken cancellationToken)
{
List <StorageAnalyticsLogEntry> entries = new List <StorageAnalyticsLogEntry>();
using (TextReader tr = new StreamReader(await blob.OpenReadAsync(cancellationToken)))
{
for (int lineNumber = 1; ; lineNumber++)
{
cancellationToken.ThrowIfCancellationRequested();
string line = await tr.ReadLineAsync();
if (line == null)
{
break;
}
Version version = TryParseVersion(line);
if (version == null)
{
string message = String.Format(CultureInfo.CurrentCulture,
"Unable to detect a version of log entry on line {1} of Storage Analytics log file '{0}'.",
blob.Name, lineNumber);
throw new FormatException(message);
}
if (version == SupportedVersion)
{
StorageAnalyticsLogEntry entry = TryParseLogEntry(line);
if (entry == null)
{
string message = String.Format(CultureInfo.CurrentCulture,
"Unable to parse the log entry on line {1} of Storage Analytics log file '{0}'.",
blob.Name, lineNumber);
throw new FormatException(message);
}
entries.Add(entry);
}
}
}
return(entries);
}
private static async Task <string> ReadBlobAsync(IStorageBlob blob, CancellationToken cancellationToken)
{
try
{
// Beware! Blob.DownloadText does not strip the BOM!
using (var stream = await blob.OpenReadAsync(cancellationToken))
using (StreamReader sr = new StreamReader(stream, detectEncodingFromByteOrderMarks: true))
{
cancellationToken.ThrowIfCancellationRequested();
string data = await sr.ReadToEndAsync();
return(data);
}
}
catch
{
return(null);
}
}
/// <summary>
/// Given a log file (as a blob), parses it and return a collection of log entries matching version 1.0
/// of the Storage Analytics Log Format.
/// </summary>
/// <param name="blob">Object representing a cloud blob with Storage Analytics log content.</param>
/// <param name="cancellationToken">A token to monitor for cancellation request.</param>
/// <returns>Collection of successfully parsed log entries.</returns>
/// <exception cref="FormatException">If unable to parse a line in given log.</exception>
/// <seealso cref="StorageAnalyticsLogEntry"/>
/// <remarks>
/// The method scans log file lines one at a time.
/// First it attempts to detect a line format version and throws an exception if failed to do so.
/// It skips all lines with version different than supported one, i.e. 1.0.
/// Then it calls TryParseLogEntry to create a log entry out of every line of supported version and throws
/// an exception if the parse method returns null.
/// </remarks>
public async Task<IEnumerable<StorageAnalyticsLogEntry>> ParseLogAsync(IStorageBlob blob,
CancellationToken cancellationToken)
{
List<StorageAnalyticsLogEntry> entries = new List<StorageAnalyticsLogEntry>();
using (TextReader tr = new StreamReader(await blob.OpenReadAsync(cancellationToken)))
{
for (int lineNumber = 1;; lineNumber++)
{
cancellationToken.ThrowIfCancellationRequested();
string line = await tr.ReadLineAsync();
if (line == null)
{
break;
}
Version version = TryParseVersion(line);
if (version == null)
{
string message = String.Format(CultureInfo.CurrentCulture,
"Unable to detect a version of log entry on line {1} of Storage Analytics log file '{0}'.",
blob.Name, lineNumber);
throw new FormatException(message);
}
if (version == supportedVersion)
{
StorageAnalyticsLogEntry entry = TryParseLogEntry(line);
if (entry == null)
{
string message = String.Format(CultureInfo.CurrentCulture,
"Unable to parse the log entry on line {1} of Storage Analytics log file '{0}'.",
blob.Name, lineNumber);
throw new FormatException(message);
}
entries.Add(entry);
}
}
}
return entries;
}
public static async Task<WatchableReadStream> TryBindStreamAsync(IStorageBlob blob, ValueBindingContext context)
{
Stream rawStream;
try
{
rawStream = await blob.OpenReadAsync(context.CancellationToken);
}
catch (StorageException exception)
{
// Testing generic error case since specific error codes are not available for FetchAttributes
// (HEAD request), including OpenRead.
if (!exception.IsNotFound())
{
throw;
}
return null;
}
return new WatchableReadStream(rawStream);
}
public static async Task <WatchableReadStream> TryBindStreamAsync(IStorageBlob blob, ValueBindingContext context)
{
Stream rawStream;
try
{
rawStream = await blob.OpenReadAsync(context.CancellationToken);
}
catch (StorageException exception)
{
// Testing generic error case since specific error codes are not available for FetchAttributes
// (HEAD request), including OpenRead.
if (!exception.IsNotFound())
{
throw;
}
return(null);
}
return(new WatchableReadStream(rawStream));
}
